The present invention relates to a vehicular headlamp employing a projection-type lamp unit.
Conventionally, a vehicular headlamp constructed so as to radiate a beam forward using, a projection-type lamp unit has been known.
The projection-type lamp unit is constructed so as to converge and reflect light from a light source, which is disposed on an optical axis extending in the lengthwise direction of a vehicle forward towards the optical axis using a reflector, and radiate the reflected light to the front of the lamp via a projection lens provided in front of the reflector. If this projection-type lamp unit is constructed for low beam radiation, a shade for partially blocking reflected light from the reflector is provided between the projection lens and the reflector.
For low-beam radiation, illuminating road zones on the sides of the vehicle and the like, in addition to the road ahead of the vehicle, is desirable. However, since the lateral diffusion angle of light radiated to the front of the lamp via the projection lens is inherently limited by the properties of the lens, there is a problem in that the projection-type lamp unit may be incapable of sufficiently illuminating the road zones on the sides of the vehicle.
Taking the foregoing into consideration, it is an object of the present invention to provide a vehicular headlamp constructed so as to radiate a beam forward in a predetermined low-beam light distribution pattern using a projection-type lamp unit and which is capable of improving visibility to the sides of the vehicle without having a significant effect on the formation of the low-beam light distribution pattern.